In a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, frame structures respectively applicable to a Frequency Division Duplex (FDD) mode and to a Time Division Duplex (TDD) mode are provided. As shown in FIG. 1, in the frame structure applicable to the FDD mode, each radio frame is 10 ms long and consists of 20 slots of length 0.5 ms, numbered from 0 to 19. A subframe i of length 1 ms consists of two consecutive slots 2i and 2i+1, where 0≦i≦9. In the frame structure applicable to the TDD mode, each radio frame of length 10 ms consists of two half-frames of length 5 ms each. Each half-frame consists of five subframes of length 1 ms. Each subframe i is defined as two slots, 2i and 2i+1, of length 0.5 ms in each subframe, where 0≦i≦9.
In the above frame structures, when a Normal Cyclic Prefix (Normal CP) is employed, seven symbols are included in a slot, and when an Extended Cyclic Prefix (Extended CP) is employed, six symbols are included in a slot.
In the LTE system, uplink power control may be performed to control transmit power of uplink physical channels, so as to compensate for channel path loss and shadow fading and suppress inter-cell interference. Uplink physical channels on which power control is performed include Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH) and Sounding Reference Signal (SRS). In the LTE system, the uplink power control is performed in a manner of combining open loop control with closed loop control.
In the LTE system, the transmit power (in dBm) of a User Equipment (UE) in a PUCCH of subframe i is defined as equation (1):PPUCCH(i)=min{PCMAX,PO—PUCCH+PL+h(nCQI,nHARQ)+ΔF—PUCCH(F)+g(i)}  (1)
In equation (1), PCMAX indicates UE Configured Maximum UE Output Power, with a range depending on multiple parameters, including Maximum UE Power depending on UE Power Class, System Configured Maximum Configuration power (IE P-Max), Maximum Configuration Output Power Tolerance (PCMAX Tolerance), Maximum Power Reduction (MPR), and Additional Maximum Power Reduction (A-MPR), etc.
In equation (1), PO—PUCCH is an open loop power control parameter, which is a sum of a cell specific value PO—NOMINAL—PUCCH and a UE specific value PO—UE—PUCCH.
In equation (1), PL is a Downlink Pathloss Estimate measured and calculated by the UE.
In equation (1), ΔF—PUCCH(F) is a power offset associated with PUCCH format (F). In the LTE system, 6 PUCCH formats are defined, i.e., PUCCH format 1/1a/1b/2/2a/2b. ΔF—PUCCH(F) is defined by taking PUCCH format 1a as a reference format. The power offset of the reference format, which configured by functionality at a high level, is 0. As shown in table 1,
TABLE 1PUCCH format (F)ΔF—PUCCH (F)1 [−2, 0, 2]1b [1, 3, 5]2 [−2, 0, 1, 2]2a[−2, 0, 2]2b[−2, 0, 2]
In equation (1), h(nCQI,nHARQ) is a value based on the PUCCH format F, where nCQI indicates the number of bits of a Channel Quality Indicator (CQI), nHARQ indicates the number of bits of a Hybrid Automatic Repeat Request (HARQ).
For PUCCH format 1/1a/1b, h(nCQI,nHARQ)=0.
For PUCCH format 2/2a/2b with normal CP,
      h    ⁡          (                        n          CQI                ,                  n          HARQ                    )        =      {                                        10            ⁢                                                  ⁢                                          log                10                            ⁡                              (                                                      n                    CQI                                    4                                )                                                                                        if              ⁢                                                          ⁢                              n                CQI                                      ≥            4                                                0                                      otherwise            .                              
For PUCCH format 2 with expended CP,
      h    ⁡          (                        n          CQI                ,                  n          HARQ                    )        =      {                                        10            ⁢                                                  ⁢                                          log                10                            ⁡                              (                                                                            n                      CQI                                        +                                          n                      HARQ                                                        4                                )                                                                                                        if                ⁢                                                                  ⁢                                  n                  CQI                                            +                              n                HARQ                                      ≥            4                                                0                                      otherwise            .                              
In equation (1), g(i) indicates a current PUCCH power control adjustment state. As shown in equation (2),
                              g          ⁡                      (            i            )                          =                              g            ⁡                          (                              i                -                1                            )                                +                                    ∑                              m                =                0                                            M                -                1                                      ⁢                                                  ⁢                                          δ                PUCCH                            ⁡                              (                                  i                  -                                      k                    m                                                  )                                                                        (        2        )            
In equation (2), for the FDD system, M=1, k0=4. That is, for the FDD system, the current PUCCH power control adjustment state g(i) in subframe i is an accumulated value of the power control adjustment state g(i−1) in subframe i−1 and an eNodeB-indicated transmit power control (TPC) command δPUCCH in subframe i−4. For the TDD system, the values of M and km are related to system uplink-downlink configurations. That is, for the TDD system, the PUCCH power control adjustment state g(i) in subframe i is an accumulated value of the power control adjustment state g(i−1) in subframe i−1 and a sum of a plurality of eNodeB-indicated transmit power control (TPC) commands δPUCCH in subframes i−k0, i−k1, . . . , i−kM-1. For the TDD system, if subframe i is not an uplink subframe, g(i)=g(i−1).
In equation (2), the transmit power control command δPUCCH is a UE specific closed loop modified value, which is transmitted by the eNodeB to a target UE in a Physical Downlink Control Channel (PDCCH). If the UE does not detect a TPC command in a subframe, δPUCCH=0 dB.
The PUCCH is used to bear uplink control information (UCI), including scheduling request (SR), positive acknowledgement/negative acknowledgement (ACK/NACK) of physical downlink shared channel (PDSCH) and downlink channel state information (CSI) feedback by the UE. There are three forms of CSI, channel quality indication (CQI), pre-coding matrix indicator (PMI) and rank indication (RI).
A LTE-Advanced system is a next generation evolution system of the LTE system. In order to support greater system bandwidth and become backward compatible with the current LTE standard, a carrier aggregation technology is introduced. FIG. 2 is a schematic view showing the implementation of carrier aggregation in the LTE-A system. As shown in FIG. 2, each aggregated carrier is referred to as a component carrier (CC) or a serving cell. The plurality of CCs may be continuous or discontinuous. In FIG. 2, for discontinuous CCs, there is a component carrier gap between the CCs, each CC may be in a same operating band or different operating bands, and may include a plurality of sub-carriers.
In order to transmit large load ACK/NACK response information, a new PUCCH format is introduced in the LTE-A system, which is referred to as PUCCH format 3. As specified in the prior art, in a FDD system, the ACK/NACK response information to be feedback includes 10 bits at most, and in a TDD system, the ACK/NACK response information to be feedback includes 20 bits at most. When the ACK/NACK response information to be feedback has more than 20 bits, a spatial bundling operation is performed on all ACK/NACK response information corresponding to PDSCHs including 2 codeword streams. That is, a logical AND operation is performed on the corresponding ACK/NACK response information. When the PUCCH format 3 transmission is employed, in the case that the number of feedback bits is less than or equal to 11, a Reed-Muller (RM) encoding scheme is employed; when the number of feedback bits is greater than 11, a dual RM encoding scheme is employed, the ACK/NACK response information to be feedback is divided into two parts, which are encoded by using the RM encoding scheme respectively and then cascaded-interleaved for transmission. However, regarding how to divide the ACK/NACK response information, no specific solution has been proposed in the prior art.
As specified in the prior art, in the LTE-A system, the UE may concurrently receive a plurality of PDSCHs in multiple configured or activated serving cells. The ACK/NACK response information of the plurality of PDSCHs is transmitted in a single PUCCH on a UE specific CC. The UE specific CC is referred to as primary component carrier (PCC), or Primary cell (Pcell).
For the LTE-A system, the PUCCH power control is performed according to equation (3). The transmit power of PUCCH format 3 in subframe i is represented by PPUCCH(i),PPUCCH(i)=min{PCMAX,c(i),P0—PUCCH+PLc+h(nCQI,nHARQ,nSR)+ΔF—PUCCH(F)+ΔTxD(F′)+g(i)}  (3)
where PCMAX,c(i) indicates the maximum transmit power of the serving cell c in subframe i, PO—PUCCH indicates an open loop power control parameter, ΔF—PUCCH(F) indicates a power offset associated with PUCCH format F, PLc indicates a downlink path loss estimate of the serving cell c measured and calculated by the UE, ΔTxD(F′) indicates a transmission diversity power compensation set according to a different PUCCH format F, with a value in a set of {0, −1, −2, −3} dB but not limited to this data set, h(nCQI,nHARQ,nSR) is a value based on the PUCCH format; as specified in the prior art, if single RM encoded PUCCH format 3 is employed and no transmission diversity is configured,
            h      ⁡              (                              n            CQI                    ,                      n            HARQ                    ,                      n            SR                          )              =                            n          HARQ                +                  n          SR                -        1            2        ,if the single RM encoded PUCCH format 3 is employed and transmission diversity is configured, or if dual RM encoded PUCCH format 3 is employed,
            h      ⁡              (                              n            CQI                    ,                      n            HARQ                    ,                      n            SR                          )              =                            n          HARQ                +                  n          SR                -        1            3        ,where nSR=1 if the current subframe is configured as an SR transmission subframe, otherwise, nSR=0, and nCQI is the number of bits of the channel quality indicator.
For the FDD system, nHARQ indicates the number of received transmission blocks. However, for the TDD system, a method for determining the nHARQ has not ever been proposed in the prior art, and thus there is no way to perform PUCCH format 3 power control according to equation (3).